Agricultural combines are large machines that harvest, thresh, separate, and clean agricultural planted harvested crops such as corn. The cleaned corn, so obtained, is stored in a corn tank on the combine. As a rule, the threshed out straw is either chopped and distributed on the fields across the width of the cutter head or conducted around the straw chopper and deposited in a swath on the field without being chopped, in order to be able pick it up subsequently with a baler. The harvested crop residue remaining at the rear outlet of the cleaning arrangement, such as chaff and small straw particles, is distributed across the field by a chaff spreader or is conducted through the straw chopper and distributed across the field.
DE 199 08 111 C describes a combine with a straw chopper and two impeller blowers, arranged side by side alongside each other, that follow the straw chopper for the widely distributed ejection of straw across the field. The outlet of the straw chopper and the inlet of the impeller blowers are arranged in a housing, that includes impeller blades rotating about an approximately vertical axis and are arranged in a single plane for the purpose of transfer of the harvested crop without changing direction. The impeller blades are fastened below the cover plate to a central, circular cylindrical shaft that is brought into rotation by means of a drive element arranged above the cover plate. The impeller blades are configured as rectangles so that their outer edges are oriented parallel to the axis of rotation and define a circular cylindrical envelope when rotated.
US 2007/0015556 A describes an impeller blower in which the straw in chopped form is thrown against the impeller blowers by means of a straw chopper at an angle from below, the impeller blowers are built up of impeller blades on an upper circular disk and extend downward radially and vertically to the surface of the disk. The impeller blades are wedge shaped, where the outer ends of the impeller blades extend to a greater distance vertically than the inner ends. The outer edges of the impeller blades (except for rather short, upper corner regions that inclined inwards) are oriented parallel to the axis of rotation, so that they define a circular, cylindrical envelope when rotated.
In the case of the known arrangement of straw choppers and following impeller blades, it is seen as detrimental on the basis of the outer edges of the impeller blades that are parallel to the axis of rotation that a certain distance must be maintained in order to avoid a collision between the straw chopper and the following impeller blade. However, problems may result in view of the distance that must be maintained in the transfer of harvested crop.